History of the atomic model
suggested matter existed in the form of very small, indivisible particles
Who was Democritus?
electrons orbited around a massive positively charged center
What is the Saturnian or Nagoaka's atomic model?
distinct spherical regions located at fixed distances from the nucleus
What are energy levels?
smallest subatomic particle
What is the electron?
an atom that has fewer electrons than the atomic number
What is a positively charged ion or cation?
Discovered the nucleus
Who? was Ernest Rutherford
Rutherford's experiment used a beam of this directed at a peice of gold foil
What is an alpha particle?
studies the behavior of matter and energy at the atomic level
What is quantum mechanics?
subatomic particles located in the atom's nucleus
What are protons and neutrons?
an atom that has more electrons than protons
What is a negatively charged atom or anion?
opposite electrical charges attract and same charges repel
What is the law of electrostatic charges?
Though not entierly workable, this model simplifies the atom and is still useful
What is the Bohr model?
electrons in the quantum-mechanical model occupy this
What is an orbital?
identifies an element and is always written in a whole number
What is the atomic number?
Copper-63 and copper -65 never have the same number of these
What are neutrons?
Imagined atoms as hard spheres of different sizes and weights
What was John Dalton?
Rutherford's gold foil experiment led this model
What is the nucleur model?
occupies most of an atom
what is empty space?
may have differing numbers of neutrons
What is an isotope?
represented as a weighted average
What is the atomic mass?
suggested negatively charged electrons imbedded in a positive substance
What is the plum pudding model by JJ Thompson?
left behind when an element is heated to high temperatures
What is an emission spectrum?
includes orbitals that shows where electrons are likely to be found
What is the quantum-mechanical model?
is 1836 times the mass of an electron
What is the proton?
The quantity of this subatomic particle represents an atom's identity
What is the proton